Japanese Prime Minister Shinzo Abe is in Boston at the start of a four-city U.S. visit that will include talks with President Barack Obama at the White House Tuesday and an unprecedented address to a joint meeting of the Congress Wednesday. The visit, coming on the 70th anniversary of the end of World War II, is underscoring the changing security and economic relationship between the United States and Japan.

Abe’s visit takes place as senior U.S. and Japanese officials unveil updated defense guidelines reflecting Japan’s greater role in its own defense. U.S. National Security Asian Affairs director Evan Madeiros said Friday the revision, the first since 1997, will significantly expand Japan’s role in the alliance and provide a mechanism for Japan to provide a wider range of support to US forces.

Japan’s U.S. ambassador, Kenichiro Sasae, told the Centers for Strategic and International Studies (CSIS) the new guidelines will be followed by security legislation in line with last year’s Cabinet decision to change the interpretation of Japan’s postwar constitution to allow it to engage in collective self-defense operations.

“For Japan, this change in our thinking on collective defense is a sea-change. It is coming after 70 years of trust and the legislation will establish a framework for Japan to further collaborate with the United States,” said Sasae.

Temple University Asian Studies professor Jeffrey Kingston in Tokyo called Abe’s new “proactive pacifism” initiative a massive transformation in Japan’s security policy and said a rising China is driving this change.

“Back in 1997, China’s defense budget was $10 billion. Last year, it was $144 billion and there’s been a lot of saber-rattling over disputed territories between the two countries. So, the rising China narrative and concerns about its hegemonic ambitions in Asia are pushing the United States and Japan closer. And, Abe is keen to secure a U.S. commitment to back it in the event of some contingency over the disputed islands in the East China Sea,” said Kingston.

But, Kingston added, domestic support for the proactive pacifism policy is weak, with 23% public approval against 68% opposition. He said the new defense guidelines could commit Japan to more than the parliament and the public support, and that could cause bilateral tensions.

Kingston said Abe’s negotiations with the U.S. on the Trans-Pacific Partnership (TPP) - a free-trade agreement involving 10 other Pacific nations - hold both economic and geopolitical importance for Japan.

“If that happens, this visit may contribute to speeding up the signing of the TPP,” said Sato.

Fast-track trade promotion authority allows a president to negotiate trade deals with Congress approving or rejecting them, but not amending them. A senior Obama Administration official said Friday that substantial progress in the bilateral talks has been made in the auto and agricultural sectors, but no breakthrough announcement is expected during the Abe visit.

Sato said he doesn’t expect the prime minister to offer any apologies for Japan’s wartime aggression, 70 years after Japan’s defeat ending World War II.

“He’s trying to celebrate this occasion by emphasizing the close working relationship between the two countries, and Japan and the U.S., in a future-oriented manner, can work together and deal with global security issues, and that is the kind of message Abe wants to portray rather than seeing this opportunity as a time to look backward emphasizing Japan’s actions during World War II or prior to that,” said Abe.

Protests by Korean-Americans, especially in San Francisco and Los Angeles, angered over the sexual slavery of so-called comfort women by Japanese troops in occupied Korea, are expected. There have also been calls by members of Congress for Japan to face up to the country’s imperialist past. California Congressman Mike Honda, a Japanese-American, is leading a group of 25 lawmakers in urging Abe to affirm previous statements of remorse by Japanese leaders to “enhance Japan’s relationship with its neighbors through a vision of long-overdue healing.”

Meanwhile, The New York Times quoted Japanese journalists and political experts as saying the Abe government is using a carrot-and-stick approach to try to silence domestic critics of his policies. The Times said it has had “a chilling effect on coverage at a time when Mr. Abe is pushing ahead with a conservative agenda to dismantle the nation’s postwar pacifist consensus and put forth more positive portrayals of Japan’s World War II-era behavior.”